As described in U.S. Pat. No. 6,676,472, generally, there are two distinct types of lighting applications. In one, direction of the light rays is relatively unimportant. In the other, light rays must be directed in a particular manner subsequent to their generation. With respect to automotive lighting, after light rays are generated by a lamp, they must by focused/dispersed according to somewhat exacting standards. The requirements for light-directed lamps, such as headlights, sidemarkers, tail lights, brake lights, directional, hazards, CHMSLs (Center, high-mounted, stop slights), differ. However, they all share the characteristic that their light rays need to be directed in some specific manner.
Lamp elements generate light rays and lenses and/or reflecting elements direct the light rays. Lamp elements generally fall into three categories: light-emitting diode (LED), incandescent and discharge.
Discharge lamps are generally characterized as having a sealed envelop filled with a gas, the atoms/ions of which, when properly excited, give off light rays. Lens elements may be categorized as refractive, Fresnel, or Total Interal Reflection (TIR). TIR lenses have the ability to gather light rays from large solid angles and redirect them efficiently.
Interior lighting systems for automotive and other vehicle applications are generally used for two purposes. One is to provide general area illumination and the other is feature lighting of specific objects, either for aesthetic or functional reasons. Traditionally, these interior lighting systems have utilized incandescent lamps for both area and feature lighting, often using lenses to control the shape and light intensity distribution of the emitted light rays. Although incandescent lamp systems can often be integrated into various vehicle interior trim components in a simple manner, various considerations do arise which complicate their use for automotive lighting. For example, where heat from the lamp could damage adjacent components or otherwise cause problems, thermal management of that heat must be implemented. Also, there is often little room in or behind a particular vehicle interior body panel or trim component for the lamp, its socket, and lensing.
More recently, distributed light systems have found use in vehicles. These may use fiber optics or other means to deliver the light rays to a desired location. The use of a lens and focusing or dispersing devices may be employed to direct the light rays. It is well known that light transparent members including for example rods, panels, films, sheets and plates, can be made into light emitting members or illuminators by grooving or notching the members in a certain pattern.
Fiber optic substrates can be made into illuminators by marring or abrading the surface of the optical fibers at various points along their length to cause a portion of the light entering one or both ends of the optical fibers to be emitted from the marred surface areas.
Increased surface marring results in increased light emission. Accordingly, the intensity of the light emitted along the length of the substrates can be varied by varying the density or aggressiveness of the surface marring.
Such areas as foot wells, door handles, seats, trucks, cargo areas, dashboards, door sills, headliners, grab handles, etc. may be illuminated using a wide combination of technologies. In addition to incandescent lights and fluorescent lighting, LED illumination, cold cathode technology, and electroluminescent technology may now find use.
Under 49 C.F.R. Part 571.101 (FMVSS 101) 5.53 Illumination, 55.3.4 Brightness of interior lamps.                (a) Any source of illumination within the passenger compartment which is forward of a transverse vertical plane 110 mm rearward of the manikin “H” point with the driver's seat in its rearmost driving position, which is not used for the controls and displays regulated by this standard, which is not a telltale, and which is capable of being illuminated while the vehicle is in motion, shall have either:                    (1) Light intensity which is manually or automatically adjustable to provide at least two levels of brightness;            (2) A single intensity that is barely discernible to a driver who has adapted to dark ambient roadway conditions; or            (3) A means of being turned off.                        
One practice in the automotive industry is utilization of all-plastic, fabricated parts, such as, but not limited to, instrument panels, interior trims, and door panels. It is known in other automotive parts areas that different, aesthetically pleasing outer class A surfaces enhance the overall appearance of the interior of automotive vehicles.
The following patent documents are related to the present invention: UK Patent Application GB 2492100A; U.S. Pat. Nos. 5,005,108; 5,549,323; 5,542,694; 5,558,364; 5,895,115; 6,062,595; 6,053,526; 6,158,867; 6,193,399; 6,464,381; 6,594,417; 6,652,128; 6,676,472; 6,974,238; 7,150,550; 7,201,588; 7,237,933; 7,299,892; 7,387,397; 7,441,801; 7,866,858; 7,987,030; 8,016,465; 8,061,861; 8,075,173; 8,162,519; 8,210,564; 8,215,810; 8,235,567; 8,256,945; 8,408,627; 8,408,766; 8,425,062; 8,449,161; 8,469,562; 8,596,803; 8,627,586; 8,816,586; 8,925,959; 8,067,556; 9,446,734, 9,376,055; and 9,481,296; and U.S. Published Applications 2003/0209889; 2009/0021459; 2009/0251917; 2010/0104780; 2010/0194080; 2011/0002138; 2012/0188779; 2012/0217767; 2013/0279188; 2013/0329447; 2014/0077531; and 2015/0307033.
U.S. published application 2013/0329447 discloses a lighting assembly comprising an optical fiber light guide panel member having a light conducting core cladded on opposite sides by cladding made of optically transparent material having a lower index of refraction than the light conducting core to cause total internal reflection of conducted light within the light conducting core at the core-cladding interface. Disruptions at one or more areas of the cladding cause conducted light within the light conducting core to be emitted from one or more areas of the panel member. Electrical circuitry is bonded to one or both sides of the cladding. One or more LEDs embedded in the panel member are electrically coupled to the electrical circuitry and optically coupled to the light conducting core.
Polymethyl methacrylate (PMMA), also known as acrylic or acrylic glass as well as by the trade names Plexiglas, Acrylite, Lucite, and Perspex among several others, is a transparent thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to glass. The same material can be utilized as a casting resin, in inks and coatings, and has many other uses.
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed.
Polymers such as PMMA and PC can be made into a diffusing polymer in a number of ways such as by adding light diffusing material such as self-reflecting particles to the polymers.
The broad concept of illuminating safety belt buckles is over 35 years old based on the patent literature. The challenges include packaging of the illuminator assembly within the buckle housing, energy management and optical quality. The following is a summary of prior art approaches to illuminating the safety belt buckle, or the environs of the buckle.
Woodham—U.S. Pat. No. 9,151,485, issued Oct. 6, 2015. FIG. 2 of the Woodham discloses a buckle assembly configured to releasably interlock with a seat belt tongue. The assembly includes a light emitting diode (LED) configured to emit a light when the seat belt tongue is not interlocked with the assembly. An optional guide is positioned at least partially within a housing and composed of a substantially light transmitting material. The LED is positioned such that the light emitted by the LED passes through the optical guide.
Morinaga—U.S. Pat. No. 4,237,586, issued Dec. 9, 1980. FIGS. 10 and 15 of Morinaga disclose an illuminated seat belt buckle with a light emitting diode 307 whose light output is projected through a light scattering lens 305i. See col. 7, 11. 36-39.
Brundidge—U.S. Pat. No. 4,365,285, issued Dec. 21, 1982. FIG. 3 of Brundidge discloses a seat belt buckle assembly with a fiber optic display 28 that is actuated by a switch 34 that toggles upon the engagement of the belt tongue with the buckle.
Eckmann—U.S. Pat. No. 4,933,818, issued Jun. 12, 1990. FIG. 3 of Eckmann is a cross-sectional view of a lighted buckle housing 10. A point of light 15 and a light outlet 16 are both in the area of the buckle opening. A light emitting diode 18 is disposed in a lamp holder 17. A light conducting path 19 is composed of several light guide segments 20, 21 and 23, which branch off a tap 22 in the light-conducting path.
Schlaps—U.S. Pat. No. 9,434,348, issued Sep. 6, 2016. FIG. 1 of Schlaps discloses a seatbelt latch circuit that can include an illumination source configured to illuminate a seatbelt latch in response to a signal. The seatbelt latch circuit can also include a status sensor configured to output a first current if the seatbelt latch is in a removed state, output a second current if the seatbelt latch is in an inserted state and output a third current if the seatbelt latch has a fault. The seatbelt latch circuit communicates with a vehicle electrical system through only two conductors.
Kawamura—U.S. Pat. No. 5,132,880, issued Jul. 21, 1992. FIG. 1 (diagrammatic) and FIG. 2 (schematic) of Kawamura disclose an illuminated seat belt buckle in which an optical fiber F transmits light to an ejector 2 formed of a light-transmitting material such as transparent plastic.
Kawamura—U.S. Pat. No. 5,149,189, issued Sep. 22, 1992. FIGS. 1 and 2 of Kawamura illustrate a seat belt buckle 1 with a luminous cover section 21. An LED is positioned within the buckle and below the luminous cover section 21.
Colvin—U.S. Pat. No. 5,181,773, issued Jan. 26, 1993. FIG. 6 of Colvin is a representative embodiment of an illuminated seat belt buckle in which an LED light source 52 is shrouded by a translucent cover portion 38.
Kawamura—U.S. Pat. No. 5,176,439, issued Jan. 5, 1993. FIG. 1 of Kawamura discloses a seat belt buckle illuminated by LEDs 1 whose light output is transmitted through a light guide 2 with total internal reflection. A V-shaped notch 2d in portion 2b of the light guide forms a reflecting prism. An ejector 20 is formed of a light-transmissive material, such as a clear polymeric material. A V-shaped recess 21 formed within the ejector also functions as a prism to reflect and guide light to the front of the ejector.
Collins et al—U.S. Pat. No. 5,438,492, issued Aug. 1, 1995. FIGS. 12 and 13 of Collins et al are, respectively, plan and side elevational views of an illuminated seat belt buckle 22. An LED 200 is placed in a chamber 202 within the buckle 22, and energized by wires routed from a plug-in connector 214.
Blackburn et al—U.S. Pat. No. 5,892,436, issued Apr. 6, 1999. FIGS. 1 and 5 of Blackburn et al illustrate a seat belt buckle illuminated by optical fibers 72 emanating from a light source 70.
Blackburn et al—U.S. Pat. No. 5,944,135, issued Aug. 31, 1999. FIG. 2 of Blackburn et al illustrates an illuminated seat belt buckle with a field effect locking indicator.
Bergkessel—U.S. Pat. No. 6,102,440, issued Aug. 15, 2000. FIG. 2 of Bergkessel shows a seat belt system fitted with a compliance light 10 and a buckle lock 24.
Griffin—US 2012/0089302, published Apr. 12, 2012. FIG. 1 of Griffin discloses a seat belt system for a vehicle which may include a plurality of seat belt assemblies each including a seat belt receptable, a light source for selectively illuminating the receptable, and a latch mechanism for releasably latching a seat belt buckle to the receptable. A controller may be operatively associated with the light source, the latch mechanism sensor, a transmission gear position sensor, and at least one of a door position sensor, engine sensor and air bag sensor. The controller may operably process signals received from the sensors and direct the light source to selectively illuminate the seat belt receptacle in various operational conditions of the vehicle.
Rogers et al—US 2001/0033492, published Oct. 25, 2001. FIG. 2 of Rogers et al illustrates an illuminated seat belt buckle in which an illuminator 54 transmits light through a U-shaped light pipe 62 to the buckle opening.
Gray et al—US 2007/0236917, published Oct. 11, 2007. Gray et al discloses a lighted and heated seat belt buckle.
Knoedl—US 2014/0268844, published Sep. 18, 2014. Knoedl discloses an illuminated seat belt buckle. FIG. 2 is an exploded isometric view of the lighting device 26 that illuminates the insertion aperture of the buckle.
Ellis et al—U.S. Pat. No. 6,558,027, issued May 6, 2003. FIG. 2 of Ellis et al discloses a push button seat belt buckle with an illuminated electroluminescent panel.
Park—U.S. Pat. No. 7,275,613, issued Oct. 2, 2007. Park discloses an automatic seat belt system that automatically unlocks if the ignition key is removed. A buckle lamp 20 is a secondary feature of the system.
Kohama—U.S. Pat. No. 7,360,794, issued Apr. 22, 2008. FIG. 2 of Kohama '794 illustrates the illumination portion of a lighted seat belt buckle. The illumination portion mounts an LED 53 in a holding board that is oriented generally transverse to the insertion direction of the belt tongue, i.e. perpendicular in the FIG. 2 embodiment.
Kohama et al—U.S. Pat. No. 7,347,579, issued Mar. 25, 2008. FIG. 1 of Kohama et al illustrates a variation of the lighted seat belt buckle of Kohama above in which LEDs mounted on holding boards 49a project light onto reflectors 52 embedded in the molded cover of the buckle.
Kohama—U.S. Pat. No. 7,569,265, issued Aug. 4, 2009. Kohama '265 uses the same reflector-based design as FIG. 1 of Kohama et al above, but adds a “Light Intensity Control Device” in series with the LED circuitry to avoid an occurrence of unevenness of brightness. This is shown schematically in FIG. 2(b), where reference numeral 53 designates an LED.
Klick et al—U.S. Pat. No. 7,942,565, issued May 17, 2011. Klick et al discloses several embodiments of an optical waveguide for receiving light from an LED and on the basis of total internal reflection changing the main radiating direction of the electromagnetic light energy.
Line et al—U.S. Pat. No. 9,211,866, issued Dec. 15, 2015. Line et al discloses an illuminated seat belt buckle which is variously described and claimed as illuminating the “vehicle interior,” or defining a “flashlight.”
Salter et al—U.S. Pat. No. 9,463,734, issued Oct. 11, 2016. Salter et al discloses an illuminated seatbelt assembly in which a “photoluminescent structure” is disposed within a buckle and is configured to luminesce in response to excitation by a light source.
Schmotzer et al—U.S. Pat. No. 9,481,318, issued Nov. 1, 2016. Schmotzer et al discloses a seat belt buckle 10 incorporating a display 14.
As used herein, the term “sensor” is used to describe a circuit or assembly that includes a sensing element and other components. In particular, as used herein, the term “magnetic field sensor” is used to describe a circuit or assembly that includes a magnetic field sensing element and electronics coupled to the magnetic field sensing element.
As used herein, the term “magnetic field sensing element” is used to describe a variety of electronic elements that can sense a magnetic field. The magnetic field sensing elements can be, but are not limited to, Hall effect elements, magnetoresistance elements, or magnettransistors. As is known, there are different types of Hall effect elements, for example, a planar Hall element, a vertical Hall element, and a circular vertical Hall (CVH) element. As is also known, there are different types of magnetoresistance elements, for example, a giant magnetoresistance (GMC) element, an anisotropic magnetoresistance element (AMR), a tunneling magnetoresistance (TMR) element, an Indian antimonide (InSb) sensor, and a magnetic tunnel junction (MTJ).
As is known, some of the above-described magnetic field sensing elements tend to have an axis of maximum sensitivity parallel to a substrate that supports the magnetic field sensing element, and others of the above-described magnetic field sensing elements tend to have an axis of maximum sensitivity perpendicular to a substrate that supports the magnetic field sensing element. In particular, planar Hall elements tend to have axes of sensitivity perpendicular to a substrate, while magnetoresistance elements and vertical Hall elements (including circular vertical Hall (CVH) sensing element) tend to have axes of sensitivity parallel to a substrate.
Magnetic field sensors are used in a variety of applications, including, but not limited to, an angle sensor that senses an angle of a direction of a magnetic field, a current sensor that senses a magnetic field generated by a current carried by a current-carrying conductor, a magnetic switch that senses the proximity of a ferromagnetic object, a rotation detector that senses passing ferromagnetic articles, for example, magnetic domains of a ring magnet, and a magnetic field sensor that senses a magnetic field density of a magnetic field.
Despite the teachings of the above patent documents, there is still a need for an easily and inexpensively manufactured assembly configured to form a light pattern proximate an opening slot of a safety belt buckle in a passenger compartment of a vehicle.